Are we ready for inexpensive, easy access to personal DNA tests?

Last October, Kristen Whitaker, a mom from Wellesley, Mass., spit into a tube, sent it to a lab that scanned her saliva for about 1 million different points on her genome--a person's genetic code--and learned from personal-genetics company 23andMe that she probably had celiac disease. An endoscopy confirmed the condition, and Whitaker--who for years had chalked up her stomach pains to irritable bowel syndrome--went on to test her three kids. She discovered that her 5-year-old, who was falling off pediatric growth charts, also had a gluten intolerance. They're both now gluten-free, and her daughter no longer cries when she eats.